Continuously variable transmissions (CVTs) utilize a ratio-varying unit (“variator”) to provide a continuous variation of transmission ratio rather than a series of predetermined ratios. The variator is coupled between the transmission input and the transmission output via gearing and one or more clutches.
In one type of continuously variable transmission, referred to as an infinitely variable transmission (IVT), a zero output speed can be obtained independently of the rotational input speed provided to the transmission by the drive unit in a geared neutral mode. Infinitely variable transmissions often use a variator and a planetary gear train to split power flow into two parts. For instance, power may flow along a first path through the variator and along a second path through the planetary gear train. Power may also be recirculated to the variator, thereby increasing the load experienced by the variator during the operation of the infinitely variable transmission. Most current architectures for infinitely variable transmissions subject the variator to the entire power load recirculated through the infinitely variable transmission.